6w6d and the line is a lot lighter? Should I be worried?

N 💛
I admit I am a POAS-aholic. I took about 7 tests the week I got my BFP and have taken it every week since, they've been getting darker and darker. Took one this morning and it's lighter than it's ever been causing me worry. 
I've already had a transvaginal ultrasound at 4w2d with a positive. And I have another dr appt on Wed to hear the heartbeat. 
Should I be concerned with this lighter line result?? 😨